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MDBX_COPY(1)		    General Commands Manual		  MDBX_COPY(1)

NAME
       mdbx_copy - MDBX	environment copy tool

SYNOPSIS
       mdbx_copy [-V] [-q] [-c]	[-d] [-p] [-n] src_path	[dest_path]

DESCRIPTION
       The  mdbx_copy  utility copies an MDBX environment. The environment can
       be copied regardless of whether it is currently in use.	No lockfile is
       created,	since it gets recreated	at need.

       If dest_path is specified it must be the	path of	an empty directory for
       storing the backup. Otherwise, the backup will be written to stdout.

OPTIONS
       -V     Write the	library	version	number to  the	standard  output,  and
	      exit.

       -q     Be quiet.

       -c     Compact  while  copying. Only current data pages will be copied;
	      freed or unused pages will be omitted from the copy. This	option
	      will slow	down the backup	process	as it is  more	CPU-intensive.
	      Currently	it fails if the	environment has	suffered a page	leak.

       -d     Alters  geometry	to  enforce  the copy to be a dynamic size DB,
	      which could be growth and	shrink by reasonable steps on the fly.

       -p     Use read transaction parking/ousting during  copying  MVCC-snap-
	      shot.   This  allows  the	 writing  transaction to oust the read
	      transaction used to copy the database if copying takes  so  long
	      that it will interfere with the recycling	old MVCC snapshots and
	      may  lead	to an overflow of the database.	 However, if the read-
	      ing transaction is ousted	the copy will be  aborted  until  suc-
	      cessful  completion.  Thus, this option allows copy the database
	      without interfering with write  transactions  and	 a  threat  of
	      database	overflow, but at the cost that copying will be aborted
	      to prevent such conditions.

       -u     Warms up the DB before copying via notifying OS kernel of	subse-
	      quent access to the database pages.

       -U     Warms up the DB before copying, notifying	the OS kernel of  sub-
	      sequent  access  to the database pages, then forcibly loads ones
	      by sequential access and tries to	lock database pages in memory.

       -n     Open MDBX	environment(s) which do	not use	subdirectories.	  This
	      is legacy	option.	For now	MDBX handles this automatically.

DIAGNOSTICS
       Exit  status  is	 zero if no errors occur.  Errors result in a non-zero
       exit status and a diagnostic message being written to standard error.

CAVEATS
       This utility can	trigger	significant file size growth if	run in	paral-
       lel with	write transactions, because pages which	they free during copy-
       ing cannot be reused until the copy is done.

SEE ALSO
       mdbx_dump(1), mdbx_chk(1), mdbx_stat(1),	mdbx_load(1) mdbx_drop(1)

AUTHOR
       Howard  Chu  of Symas Corporation <http://www.symas.com>, Leonid	Yuriev
       <https://gitflic.ru/user/erthink>

MDBX 0.13			  2024-08-29			  MDBX_COPY(1)

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